On the forward–backward spatial APES

In this fast communication, we examine non-parametric data-adaptive spatial spectrum estimation using an array of sensors. We derive a forward–backward (FB) version of the recent spatial APES (SAPES) beamformer, and show that the SAPES algorithm is robust to the case of pairwise coherent sources. Numerical simulations indicate that the proposed FB version of SAPES offers higher resolution than the forward-only SAPES algorithm.